1. Field of the Invention
This invention relates to storage rack shelving of the type used in multilevel storage racks, which shelving is of corrugated metal construction with transversely extending channels which have openings of selected size to provide for controlled flow of sprinkler fluid thereout.
2. Description of the Prior Art
When storing goods on multilevel storage racks it is important to be able to provide adequate fire protection for all the levels of stored goods, and to provide for rearrangement of the racks as desired.
The most practical manner of providing fire protection is with overhead sprinklers, which involves pipe runs secured to the ceiling of the storage facility with sprinklerheads at selected locations.
The use of sprinkler heads, which are activated at designated temperatures, and discharge sprinkler fluid downwardly in a bell shaped pattern is satisfactory when the fire is on the topmost level of shelving. However, the sprinkler fluid is unable to penetrate layers of stacked material, and runs off over the edges of the material and down past lower level shelving and possible lower level fire locations.
Various solutions have been proposed to provide fire protection for lower level shelving, the most common of which is to locate sprinkler heads at each level, which is prohibitively expensive, not readily relocatable if the shelving is moved, and subjects the sprinkler heads to damage due to their proximity to the stored goods, which are frequently placed and replaced.
It has also been proposed to use open or wiremesh decking to permit the sprinkler fluid to flow between and down to lower levels of decking. With open mesh decking sprinkler fluid will not flow under the loads on each level, but will flow out over the stacked goods and miss goods at lower levels. Open decking also allows hot air to flow upwardly causing a chimney effect, with the result that the fire spreads quickly, can cause extensive uncontrolled damage, and even overwhelm the sprinkler system.
The U.S. Patent to Harkness U.S. Pat. No. 340,210 illustrates the common form of providing fixed fire protection at various levels by using sprinklers mounted to ceilings and which direct the fluid downwardly. No provisions for controlled sprinkler fluid flow to lower locations is suggested.
The U.S. Patent to E. M. Beland, et al U.S. Pat. No. 1,587,693 discloses a detachable cover for sinks, that is a metal plate with longitudinal corrugations, with perforations to permit water to drain from the concaved parts of the corrugations. No suggestion of use in storage racks is contemplated, no sizing and selected location of openings to permit fluid to flow out at a controlled rate, and to inhibit the upward flow of hot gas and fire.
The U.S. patent to Seiz U.S. Pat. No. 3,626,487 discloses fire and vermin resistant storage structure having fail-safe features. The structure includes upright members with shelves at selected locations, the upright members include a wet upright which has a conduit therein and sprinkler pipes extending between uprights carrying sprinkler heads at each storage level for discharge of water as required. The Seiz structure is typical of prior art structures which are very costly, immovable, and provide sprinklers at each level which results in all the attendant problems that the present invention avoids.
The U.S. Patent to Seiz U.S. Pat. No. 3,814,034 is a continuation in part of the application which formed the parent for Seiz U.S. Pat. No. 3,626,487. The Seiz patent discloses load supports for storage structures, which consists of beams 16, which horzontally span uprights 13, 14 and carry support members 19 which support the goods. The support members 19 are spaced apart at their meeting edges to permit fire retardant material to flow out. However, there are no channels in Seiz as described in the present invention which confine the sprinkler fluid, and directs its flow across the width of the supports, nor is the flow controlled in any manner. The open slots formed by Seiz's members 19 would permit smoke and gas to flow upwardly, which the present invention does not permit, and would not result in a controlled discharge of water onto the goods at lower levels. It should also be noted that Seiz provides sprinklers at all levels where goods are stored, and requires that at least one of the uprights 13 carry the fire retardant material. The Seiz structure has all of the problems that the present invention avoids.
The U.S. Patent to Heft U.S. Pat. No. 3,986,462 discloses a deck structure for racks that includes upright members with shelf beam members connecting them together, and with shelving members on the shelf beams. The shelving members have large openings therealong, and no channels to carry water under loads at the shelf beams, which blocks the fluid from lower levels. The openings in the shelving members would not control the flow of fluid, and would permit hot gases from below to flow upwardly.
The storage rack shelving of the invention does not suffer from the prior art shortcomings, and provides improved controlled fire protection for multilevel storage shelving.